Arndt Vogel

A comparison of fibrosis progression in chronic liver diseases

BACKGROUND/AIMS No study has compared the liver fibrosis progression rates among chronic liver diseases and the risk factors in order to better organize screening strategies. METHODS A total of 4852 patients were retrospectively studied (chronic hepatitis C (HCV) [n=2313], human immunodeficiency virus (HIV)-HCV co-infection (HIV-HCV [n=180]), hepatitis B (HBV [n=777]), alcoholic liver disease (ALD [n=701]), primary biliary cirrhosis (PBC [n=406]), genetic hemochromatosis (GH [n=383]) auto-immune hepatitis (AIH [n=57]) and delta hepatitis (n=35). The fibrosis progression rates were estimated from birth and from the date of exposure, when known, to the first biopsy. RESULTS There were highly significant differences in the rates of fibrosis progression, the most rapid being HIV-HCV co-infection (50% cirrhosis percentile at 52 years of age) and the slowest being PBC (50% cirrhosis percentile at 81 years). There was an acceleration of fibrosis progression with aging. Fibrosis progression was slower in females compared with males for HCV, HBV, GH, and PBC. In contrast, in ALD, the fibrosis progression was more rapid in females. CONCLUSIONS Rates of fibrosis progression differ markedly between the predominant causes of chronic liver disease, and according to age and gender. Patients with HIV-HCV co-infection are at particularly high risk of fibrosis progression.

Effect of Everolimus on Survival in Advanced Hepatocellular Carcinoma After Failure of Sorafenib The EVOLVE-1 Randomized Clinical Trial

IMPORTANCE Aside from the multikinase inhibitor sorafenib, there are no effective systemic therapies for the treatment of advanced hepatocellular carcinoma. OBJECTIVE To assess the efficacy of everolimus in patients with advanced hepatocellular carcinoma for whom sorafenib treatment failed. DESIGN, SETTING, AND PARTICIPANTS EVOLVE-1 was a randomized, double-blind, phase 3 study conducted among 546 adults with Barcelona Clinic Liver Cancer stage B or C hepatocellular carcinoma and Child-Pugh A liver function whose disease progressed during or after sorafenib or who were intolerant of sorafenib. Patients were enrolled from 17 countries between May 2010 and March 2012. Randomization was stratified by region (Asia vs rest of world) and macrovascular invasion (present vs absent). INTERVENTIONS Everolimus, 7.5 mg/d, or matching placebo, both given in combination with best supportive care and continued until disease progression or intolerable toxicity. Per the 2:1 randomization scheme, 362 patients were randomized to the everolimus group and 184 patients to the placebo group. MAIN OUTCOMES AND MEASURES The primary end point was overall survival. Secondary end points included time to progression and the disease control rate (the percentage of patients with a best overall response of complete or partial response or stable disease). RESULTS No significant difference in overall survival was seen between treatment groups, with 303 deaths (83.7%) in the everolimus group and 151 deaths (82.1%) in the placebo group (hazard ratio [HR], 1.05; 95% CI, 0.86-1.27; P = .68; median overall survival, 7.6 months with everolimus, 7.3 months with placebo). Median time to progression with everolimus and placebo was 3.0 months and 2.6 months, respectively (HR, 0.93; 95% CI, 0.75-1.15), and disease control rate was 56.1% and 45.1%, respectively (P = .01). The most common grade 3/4 adverse events for everolimus vs placebo were anemia (7.8% vs 3.3%, respectively), asthenia (7.8% vs 5.5%, respectively), and decreased appetite (6.1% vs 0.5%, respectively). No patients experienced hepatitis C viral flare. Based on central laboratory results, hepatitis B viral reactivation was experienced by 39 patients (29 everolimus, 10 placebo); all cases were asymptomatic, but 3 everolimus recipients discontinued therapy. CONCLUSIONS AND RELEVANCE Everolimus did not improve overall survival in patients with advanced hepatocellular carcinoma whose disease progressed during or after receiving sorafenib or who were intolerant of sorafenib. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01035229.

Variation of hepatic glucuronidation : Novel functional polymorphisms of the UDP-glucuronosyltransferase UGT1A4

UDP‐glucuronosyltransferases are a family of drug metabolizing enzymes contributing to hepatic drug metabolism and protection against environmental toxins. The aim of this study was to identify polymorphisms at the human UGT1A gene locus and to characterize their function and potential association with hepatocellular carcinoma (HCC). Genomic DNA from the blood of 363 subjects (128 patients with HCC, 235 blood donors) was analyzed for polymorphisms of the UGT1A3, UGT1A4, UGT1A8, UGT1A9, UGT1A10 genes using polymerase chain reaction, sequencing analysis. Recombinant variant UGT protein was analyzed by activity assays. In the UGT1A8 gene an A173G variant and a conserved G to A exchange at position 765 were detected in 25% and 15%. UGT1A9 exhibited two variants C3Y and M33T in 1% and 3%. UGT1A10 exhibited conserved nucleotide exchanges (128 G→A and 696 C→T) in 2% and 13%. In the UGT1A3 gene a W11R, a V47A variant, and a conserved G to A exchange at position 81 with an incidence of 65%, 58%, and 65%, respectively, were identified. UGT1A4 exhibited a P24T and an L48V variant in 8% and 9%. UGT1A SNPs were not associated with HCC. UGT1A4 P24T and L48V exhibited reduced glucuronidation activities: β‐naphthylamine 30% and 50%, and dihydrotestosterone 50% and 0%, respectively. In conclusion, the high prevalence of SNPs throughout the human UGT1A gene locus illustrates a genetic basis of interindividual variations of hepatic metabolism. Two polymorphisms of the hepatic UGT1A4 protein show a differential metabolic activity toward mutagenic amines and endogenous steroids, altering hepatic metabolism and detoxification. (HEPATOLOGY 2004;39:970–977.)

Autoimmune hepatitis, from mechanisms to therapy.

In 1950, Waldenström was the first to describe a chronic form of hepatitis in young women. Subsequently, the disease was found to be associated with other autoimmune syndromes and was later termed “lupoid hepatitis” because of the presence of antinuclear antibodies. In 1965, it became designated by Mackay et al. as “autoimmune hepatitis” at an international meeting, at which the general concept of autoimmunity was endorsed by the scientific community. In the early 1960s and 1970s, the value of immunosuppressive therapy with glucocorticoids and/or azathioprine was well documented in several studies. The original association of autoimmune hepatitis (AIH) and HLA alleles, which has remarkably stood the test of time, was published in 1972. In the 1970s and 1980s, several autoantibodies were identified in patients with autoimmune hepatitis directed against proteins of the endoplasmatic reticulum expressed in liver and kidney and against soluble liver antigens. Subsequently, the molecular targets of these antibodies were identified and more precisely characterized. In the last two decades many additional pieces of the AIH puzzle have been collected leading to the identification of additional antibodies and genes associated with AIH and to the emergence of new therapeutic agents. Meanwhile, the immunoserological and genetic heterogeneity of AIH is well established and it has become obvious that clinical manifestations, disease behavior, and treatment outcome may vary by racial groups, geographical regions and genetic predisposition. Currently, the International Autoimmune hepatitis group is endorsing multi‐center collaborative studies to more precisely define the features at disease presentation and to define prognostic indices and appropriate treatment algorithms. Given the importance of serological testing, the IAHG is also working on guidelines and procedures for more reliable and standardized testing of autoantibodies. (Hepatology 2006;43;S132–S144.)

Nuclear factor-eythroid 2-related factor 2 prevents alcohol-induced fulminant liver injury

BACKGROUND & AIMS The transcription factor nuclear factor-eythroid 2-related factor 2 (Nrf2(-/-)) is essential for protecting cells against xenobiotic and oxidative stress. Increased oxidative stress has been implicated in the pathophysiology of many diseases including ethanol-induced liver disease. Therefore, the role of Nrf2(-/-) in ethanol-induced liver injury was investigated. METHODS Wild-type and Nrf2(-/-) mice were fed with the ethanol diet, followed by examination of liver pathology, mortality, and ethanol metabolism. RESULTS Nrf2(-/-) mice displayed a dramatically increased mortality associated with liver failure when fed doses of ethanol that were tolerated by WT mice. Nrf2(-/-) mice showed a significantly reduced ability to detoxify acetaldehyde, leading to an accumulation of the toxic metabolite. Loss of Nrf2(-/-) caused a marked steatosis in livers of ethanol-fed mice, and Srebp1 was identified as a candidate transcription factor responsible for lipogenic enzyme induction. Furthermore, ethanol consumption led to a progressive depletion of total and mitochondrial reduced glutathione, which was associated with more pronounced structural and functional changes to mitochondria of Nrf2(-/-) mice. In addition, ethanol feeding elicited an aggravated inflammatory response mediated by Kupffer cells in Nrf2(-/-) mice as shown by an increased tumor necrosis factor-alpha secretion and activation of the interleukin-6/Stat-3 pathway. Together these changes lead to a vicious cycle of accumulating hepatocellular damage, ultimately leading to liver failure and death of Nrf2(-/-) mice. CONCLUSIONS Our data establish a central role for Nrf2(-/-) in the protection against ethanol-induced liver injury.

Polymorphisms of the human UDP-glucuronosyltransferase (UGT) 1A7 gene in colorectal cancer

Background: Genetic polymorphisms in the human UDP-glucuronosyltransferase-1A7 (UGT1A7) gene are detected and significantly correlated with sporadic colorectal carcinoma. UGT1A7, which has recently been demonstrated to glucuronidate environmental carcinogens, is now implicated as a cancer risk gene. A silent mutation at codon 11 and missense mutations at codons 129, 131, and 208 lead to the description of three polymorphic alleles designated UGT1A7*2, UGT1A7*3, and UGT1A7*4. Methods: UGT1A7 polymorphisms were analysed by polymerase chain reaction amplification and sequencing, as well as temperature gradient gel electrophoresis in 210 healthy blood donors and 78 subjects with colorectal cancer. Results: Homozygous wild-type UGT1A7 alleles were present in 20% of normal controls but were only detected in 9% of patients with colorectal carcinoma (odds ratio (OR) 0.39 (95% confidence interval (CI) 0.17–0.92); p=0.03). Analysis of individual polymorphic alleles identified a highly significant association between the presence of UGT1A7*3 alleles and colorectal cancer (OR 2.75 (95% CI 1.6 – 4.71); p<0.001). Recombinant expression of UGT1A7 polymorphic cDNA in eukaryotic cell culture showed reduced carcinogen glucuronidation activity in comparison with wild-type UGT1A7. UGT1A7 may therefore represent a modifier gene in colorectal carcinogenesis. Conclusion: We have identified a potential novel risk factor in sporadic colorectal cancer which may contribute to the identification of risk groups and to the elucidation of factors involved in colon carcinogenesis.

Long-term outcome of liver transplantation for autoimmune hepatitis

Abstract:  Background:  Liver transplantation is the final therapeutic option for about 10% of patients with autoimmune hepatitis (AIH) who do not respond to medical therapy. The aim of this study was to evaluate the long‐term outcome in serologically defined subgroups of AIH after transplantation.

The genetic background of autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy and its autoimmune disease components

Autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy (APECED) is a rare autosomal recessive disorder characterized by an immune-mediated destruction of endocrine tissues, chronic candidiasis, and additional ectodermal disorders. In contrast to many other autoimmune diseases, APECED is associated with mutations of a single gene, designated autoimmune regulator (AIRE). To date, 45 different mutations of the AIRE gene have been identified and are distributed throughout the entire coding region. Several of the AIRE mutations predict the transcription and translation of a truncated protein, which may be nonfunctional. In contrast to the genetic background of APECED, in all of the autoimmune conditions typically associated with APECED the conclusive role of a single genetic locus capable of providing insight into the etiology of the disease has not been identified. Here we provide an overview of the current clinical and genetic features of APECED in comparison to the genetic background of the frequently associated disease components of APECED.

MicroRNA‐221 overexpression accelerates hepatocyte proliferation during liver regeneration

The tightly controlled replication of hepatocytes in liver regeneration and uncontrolled proliferation of tumor cells in hepatocellular carcinoma (HCC) are often modulated by common regulatory pathways. Several microRNAs (miRNAs) are involved in HCC progression by modulating posttranscriptional expression of multiple target genes. miR‐221, which is frequently up‐regulated in HCCs, delays fulminant liver failure in mice by inhibiting apoptosis, indicating a pleiotropic role of miR‐221 in hepatocytes. Here, we hypothesize that modulation of miR‐221 targets in primary hepatocytes enhances proliferation, providing novel clues for enhanced liver regeneration. We demonstrate that miR‐221 enhances proliferation of in vitro cultivated primary hepatocytes. Furthermore, applying two‐thirds partial hepatectomy as a surgically induced liver regeneration model we show that adeno‐associated virus‐mediated overexpression of miR‐221 in the mouse liver also accelerates hepatocyte proliferation in vivo. miR‐221 overexpression leads to rapid S‐phase entry of hepatocytes during liver regeneration. In addition to the known targets p27 and p57, we identify Aryl hydrocarbon nuclear translocator (Arnt) messenger RNA (mRNA) as a novel target of miR‐221, which contributes to the pro‐proliferative activity of miR‐221. Conclusion: miR‐221 overexpression accelerates hepatocyte proliferation. Pharmacological intervention targeting miR‐221 may thus be therapeutically beneficial in liver failure by preventing apoptosis and by inducing liver regeneration. (HEPATOLOGY 2013;)

Loss of Imprinting and Allelic Switching at the DLK1-MEG3 Locus in Human Hepatocellular Carcinoma

Deregulation of imprinted genes is an important molecular mechanism contributing to the development of cancer in humans. However, knowledge about imprinting defects in human hepatocellular carcinoma (HCC), the third leading cause of cancer mortality worldwide, is still limited. Therefore, a systematic meta-analysis of the expression of 223 imprinted loci in human HCC was initiated. This screen revealed that the DLK1-MEG3 locus is frequently deregulated in HCC. Deregulation of DLK1 and MEG3 expression accompanied by extensive aberrations in DNA methylation could be confirmed experimentally in an independent series of human HCC (n = 40) in more than 80% of cases. Loss of methylation at the DLK1-MEG3 locus correlates linearly with global loss of DNA methylation in HCC (r2 = 0.63, p<0.0001). Inhibition of DNMT1 in HCC cells using siRNA led to a reduction in MEG3-DMR methylation and concomitant increase in MEG3 RNA expression. Allele-specific expression analysis identified loss of imprinting in 10 out of 31 informative samples (32%), rendering it one of the most frequent molecular defects in human HCC. In 2 cases unequivocal gain of bi-allelic expression accompanied by substantial loss of methylation at the IG-DMR could be demonstrated. In 8 cases the tumour cells displayed allelic switching by mono-allelic expression of the normally imprinted allele. Allelic switching was accompanied by gains or losses of DNA methylation primarily at IG-DMR1. Analysis of 10 hepatocellular adenomas (HCA) and 5 cases of focal nodular hyperplasia (FNH) confirmed that this epigenetic instability is specifically associated with the process of malignant transformation and not linked to increased proliferation per se. This widespread imprint instability in human HCC has to be considered in order to minimize unwanted side-effects of therapeutic approaches targeting the DNA methylation machinery. It might also serve in the future as predictive biomarker and for monitoring response to epigenetic therapy.